public class Words {
    private Words() { };  // Uninstantiable

    public static final String FIRST  = "the";
    public static final String SECOND = null;
    public static final String THIRD  = "set";
} 

// The second version of the Words class appears below (commented out)
//
// public class Words {
//     private Words() { };  // Uninstantiable
//
//     public static final String FIRST  = "physics";
//     public static final String SECOND = "chemistry";
//     public static final String THIRD  = "biology";
// }